JP6201152B2 - Heat ray shielding film, heat ray shielding transparent base material, automobile and building - Google Patents

Description

  The present invention relates to a heat ray shielding film having good visible light transmittance and an excellent heat ray shielding function, a heat ray shielding transparent base material, an automobile on which the heat ray shielding transparent base material is mounted as a window material, and the heat ray shielding transparency. The present invention relates to a building in which a base material is used as a window material.

  Sun rays are roughly divided into three types: near infrared light (heat rays), visible light, and ultraviolet light. The heat ray is a wavelength region that is perceived by the human body as heat energy, and causes a rise in indoor temperature in summer. In addition, it has been pointed out that the ultraviolet region adversely affects the human body such as sunburn and skin cancer.

In recent years, in order to shield near-infrared rays as heat rays and to impart heat retention and heat insulation performance, it has been proposed to impart near-infrared absorbing ability to transparent substrates such as glass, polycarbonate resin, and acrylic resin.
For example, in Patent Document 1, at least one selected from the group consisting of Group IIIa, Group IVa, Group Vb, Group VIb and Group VIIb of the periodic table as a first layer from the substrate side on a transparent glass substrate. A composite tungsten oxide film containing metal ions is provided, a transparent dielectric film is provided as a second layer on the first layer, a group IIIa of the periodic table as a third layer on the transparent dielectric film of the second layer, A composite tungsten oxide film containing at least one metal ion selected from the group consisting of IVa group, Vb group, VIb group and VIIb group is provided, and the refractive index of the transparent dielectric film constituting the second layer Is made lower than the refractive index of the composite tungsten oxide film of the first layer and the third layer, so that the heat ray-shielding glass can be suitably used in a portion where high visible light transmittance and good heat ray shielding performance are required. It has been proposed.

  Further, in Patent Document 2, a first dielectric film is provided as a first layer from the substrate side on a transparent glass substrate in the same manner as Patent Document 1, and the second layer is oxidized on the first layer. There has been proposed a heat ray-shielding glass in which a tungsten film is provided and the second-layer dielectric film is provided as a third layer on the second layer.

  In Patent Document 3, a composite tungsten oxide film containing the same metal element is provided as a first layer from the substrate side on the transparent substrate by the same method as Patent Document 1, and the first layer is formed on the first layer. Heat ray blocking glass having a transparent dielectric film as two layers has been proposed.

Further, in Patent Document 4, tungsten trioxide (WO ₃ ), molybdenum trioxide (MoO ₃ ), niobium pentoxide (Nb ₂ O ₅ ), and tantalum pentoxide containing additional elements such as hydrogen, lithium, sodium, and potassium. A metal oxide film selected from one or more of (Ta ₂ O ₅ ), vanadium pentoxide (V ₂ O ₅ ), and vanadium dioxide (VO ₂ ) is coated on a glass sheet by a CVD method or a spray method, and 250 A solar control glass sheet having solar light shielding properties formed by thermal decomposition at about ° C. has been proposed.

  In Patent Document 5, a tungsten oxide obtained by hydrolyzing tungstic acid is used, and an organic polymer having a specific structure called polyvinylpyrrolidone is added to the tungsten oxide, so that when sunlight is irradiated, Is absorbed by the tungsten oxide to generate excited electrons and holes, and the appearance of pentavalent tungsten is remarkably increased by a small amount of ultraviolet light, and the coloring reaction is accelerated. In addition, the property that the pentavalent tungsten is oxidized to hexavalent very quickly by blocking the light and the decoloring reaction becomes fast, and the coloring and decoloring reaction to sunlight is fast. There has been proposed a sunlight-modulable light-insulating material that has an absorption peak at 1250 nm and can block near-infrared rays of sunlight.

  In Patent Document 6, tungsten trichloride or its solvent is obtained by dissolving tungsten hexachloride in alcohol and evaporating the solvent as it is, or evaporating the solvent after heating to reflux, and then heating at 100 ° C. to 500 ° C. A powder composed of a hydrate or a mixture of both can be obtained, an electrochromic device can be obtained using the tungsten oxide fine particles, and when a proton is introduced into the film, a multilayer stack is formed. It has been proposed that optical characteristics can be changed.

Further, in Patent Document 7, meta-type ammonium tungstate and various water-soluble metal salts are used as raw materials, and heated to about 300 to 700 ° C., the inert gas (addition amount; about By supplying hydrogen gas to which 50 vol% or more or water vapor (added amount; about 15 vol% or less) is added, MxWO ₃ (M: metal element such as alkali group Ia, group IIa, rare earth, 0 <x <1 ) Have been proposed for preparing various tungsten bronzes.

JP-A-8-59300 JP-A-8-12378 JP-A-8-283044 JP 2000-1119045 A JP-A-9-127559 JP 2003-121884 A JP-A-8-73223 Japanese Patent No. 4096205

  However, according to the study by the present inventors, the near-infrared shielding bodies (heat ray shielding glass) described in Patent Documents 1 to 3 mainly include sputtering, vapor deposition, ion plating, and chemical vapor deposition (CVD). Since it is manufactured by a method using a dry method such as a vacuum film formation method, there is a problem that a large manufacturing apparatus is required and the manufacturing cost is increased. In addition, since the near-infrared shielding base material is exposed to high-temperature plasma or needs to be heated after film formation because it is manufactured by the vacuum film forming method, a film or the like is used instead of glass. In the case of using the above resin as a base material, it was necessary to separately examine the film forming conditions on equipment.

  Moreover, the near-infrared shielding body (solar control glass sheet) described in Patent Document 4 forms a metal oxide film as a raw material on glass by a CVD method or a combination of a spray method and a thermal decomposition method. Since the precursor raw material is expensive and decomposes at high temperature, it is necessary to separately examine the film forming conditions when using a resin such as a film instead of a glass sheet as a base material. .

  Further, the sunlight-modulable light insulating material described in Patent Document 5 and the electrochromic element described in Patent Document 6 are materials that change their color tone by ultraviolet rays or a potential difference, and thus have a complicated film structure. There is a problem that it is difficult to apply to application fields where change is not desired.

  Furthermore, Patent Document 7 describes a method for preparing tungsten bronze, but there is no description of the particle diameter and optical characteristics of the obtained powder. This is because, in Patent Document 7, tungsten bronze is considered to be an electrolysis device, a fuel cell electrode material, and an organic synthesis catalyst material, and the above-described near-infrared shield is not used.

  On the other hand, Patent Document 8 proposes tungsten oxide fine particles and / or composite tungsten oxide fine particles used for the production of a near-infrared shield, and these oxide fine particles have excellent visible light transmittance and good near infrared rays. Has a shielding effect. For this reason, it attracts attention as a near-infrared shield that is suitably used in the fields of various buildings and vehicle window materials. However, there is a problem that the heat ray shielding function is not sufficient when a high visible light transmittance is required.

  Furthermore, in the market, the heat shield function will be further improved in terms of improving comfort in automobiles and buildings, improving fuel efficiency by reducing automobile air-conditioner loads, and saving energy by reducing air-conditioner loads in buildings. The demand is high.

  The present invention has been made paying attention to the above problems. The problem to be solved is a heat ray-shielding transparent substrate produced by forming a heat ray-shielding film having excellent heat-shielding properties and an appropriate color tone on the surface of the transparent substrate, It is providing the motor vehicle in which the heat ray shielding transparent base material is mounted as a window material, and the building in which the heat ray shielding transparent base material is used as a window material.

In order to solve the above problems, the present inventors first studied a method for improving the heat ray shielding characteristics while maintaining a high visible light transmittance. Then, attention was paid to the wavelength distribution of the polyvalent coefficient used in the visible light transmittance calculation described in JIS R 3106.
Specifically, the wavelength distribution of the weight coefficient used for calculating the visible light transmittance and the solar radiation energy in the short wavelength region were studied in detail. The inventors have obtained knowledge that it is possible to reduce only the solar radiation transmittance while keeping the visible light transmittance high by appropriately shielding the short wavelength region of visible light.

  The above findings will be further described. In the prior art, when an ultraviolet shielding agent is added to the near-infrared shielding body, it is common sense to use an ultraviolet shielding agent that does not cut the visible light region as much as possible in order to prevent any decrease in visible light transmittance. However, in spite of the common sense, the present inventors strongly absorb ultraviolet light from a wavelength of 300 nm to 380 nm and visible light from a wavelength of 380 nm to 480 nm, while being a region that greatly contributes to calculation of visible light transmittance. The present inventors have conceived a configuration in which a material having no absorption near 550 nm is allowed to coexist with the composite tungsten oxide fine particles as a selective wavelength absorbing material.

However, it has been expected that the color of the transparent base material changes when the above-described selective wavelength absorbing material that absorbs visible light coexists with the composite tungsten oxide fine particles. Then, the present inventors next performed spectral transmittance measurement of a transparent substrate on which a heat ray shielding dispersion in which a selective wavelength absorbing material and composite tungsten oxide fine particles coexisted was formed. Then, from the spectral transmittance measurement result of the transparent substrate, the tint value calculated based on JIS Z 8701, and the yellowness of the plastic calculated based on JIS K 7373 from the tint value (in the present invention, “YI” ) Was used as an index.
As a result of the examination, the wavelength that does not absorb near the wavelength of 550 nm, which is a region that greatly contributes to the calculation of the visible light transmittance, and has a large influence on the YI of the transparent substrate on which the heat ray shielding dispersion is formed. The present invention has been completed by conceiving a novel configuration in which a material having no absorption near 460 nm and having a large absorption near a wavelength of 420 nm coexists with composite tungsten oxide fine particles as a selective wavelength absorbing material.

第５の発明は、
前記選択波長吸収材料が、〔化学式１〕で示されるインドール化合物であり、式中のＲがメチル基であることを特徴とする熱線遮蔽膜である。
〔化学式１〕

第６の発明は、
前記熱線遮蔽膜が、さらに紫外線吸収剤を含有することを特徴とする熱線遮蔽膜である。
第７の発明は、
前記紫外線吸収剤が、ベンゾトリアゾール化合物、ベンゾフェノン化合物から選択される少なくとも１種であることを特徴とする熱線遮蔽膜である。
第８の発明は、
前記熱線遮蔽膜中における前記紫外線吸収剤の含有率が０．５質量％以上１０．０質量％以下であることを特徴とする熱線遮蔽膜である。
第９の発明は、
前記選択波長吸収材料が、波長５５０ｎｍの光の透過率が９０％以上であり、且つ、波長４６０ｎｍの光の透過率が９０％以上のとき、波長４２０ｎｍの光の透過率が１５％以下の透過プロファイルを有することを特徴とする熱線遮蔽膜である。
第１０の発明は、
前記無機バインダーが、シリカバインダーであることを特徴とする熱線遮蔽膜である。
第１１の発明は、
前記熱線遮蔽膜が、さらに赤外線吸収性有機化合物を含むことを特徴とする熱線遮蔽膜である。
第１２の発明は、
前記赤外線吸収性有機化合物が、フタロシアニン化合物、ナフタロシアニン化合物、イモニウム化合物、ジイモニウム化合物、ポリメチン化合物、ジフェニルメタン化合物、トリフェニルメタン化合物、キノン化合物、アゾ化合物、ペンタジエン化合物、アゾメチン化合物、スクアリリウム化合物、有機金属錯体、シアニン化合物から選択される少なくとも１種であることを特徴とする熱線遮蔽膜である。
第１３の発明は、
前記赤外線吸収性有機化合物が、フタロシアニン化合物、ジイモニウム化合物から選択される少なくとも１種であることを特徴とする熱線遮蔽膜である。
第１４の発明は、
前記赤外線吸収性有機化合物と前記複合タングステン酸化物微粒子との重量比が、（複合タングステン酸化物微粒子／赤外線吸収性有機化合物）＝１００／５〜１００／１００の範囲であることを特徴とする熱線遮蔽膜である。
第１５の発明は、
透明基材の少なくとも片面上に、第１から第１４のいずれかの発明に記載の熱線遮蔽膜が形成されていることを特徴とする熱線遮蔽透明基材である。
第１６の発明は、
前記透明基材がガラスであることを特徴とする熱線遮蔽透明基材である。
第１７の発明は、
ＪＩＳ Ｋ ７３７３で算出される黄色度（ＹＩ）が、−２０．０以上１０．０以下であることを特徴とする熱線遮蔽透明基材である。
第１８の発明は、
ＪＩＳ Ｋ ７３７３で算出される黄色度（ＹＩ）が−２０．０以上５．０以下であることを特徴とする熱線遮蔽透明基材である。
第１９の発明は、
ＪＩＳ Ｒ ３１０６で算出される可視光透過率が７０％以上であり、且つ、可視光透過率が７０％以上のときの日射透過率が３２．５％以下であることを特徴とする熱線遮蔽透明基材である。
第２０の発明は、
第１５から第１９の発明のいずれかに記載の熱線遮蔽透明基材が、窓材として搭載されていることを特徴とする自動車である。
第２１の発明は、
第１５から第１９の発明のいずれかに記載の熱線遮蔽透明基材が、窓材として使用されていることを特徴とする建造物である。 That is, the first invention for solving the above-described problem is:
Formula _M y WO _Z (where, M is, Cs, Rb, K, Tl , In, Ba, Li, Ca, Sr, Fe, 1 or more elements selected Sn, Sb, Al, from Cu, 0 0.1 ≦ y ≦ 0.5, 2.2 ≦ z ≦ 3.0), and a composite tungsten oxide fine particle having a hexagonal crystal structure, a selective wavelength absorbing material, and an inorganic binder A heat shielding film,
The selective wavelength absorbing material is an indole compound;
The weight ratio of the composite tungsten oxide fine particles to the selective wavelength absorbing material is in the range of (composite tungsten oxide fine particles / selective wavelength absorbing material) = 100/2 to 100/800,
The selective wavelength absorbing material has a transmittance of light having a wavelength of 550 nm of 90% or more and a transmittance of light having a wavelength of 420 nm when the transmittance of light having a wavelength of 460 nm is 90% or more. It is a heat ray shielding film characterized by having a profile.
The second invention is
The composite tungsten oxide fine particle is at least one selected from Cs _0.33 WO ₃ and Rb _0.33 WO ₃ .
The third invention is
The composite tungsten oxide fine particles are fine particles having a dispersed particle diameter of 40 nm or less.
The fourth invention is:
The selective wavelength absorbing material is an indole compound represented by [Chemical Formula 1], and R in the formula is an alkyl group having 1 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms. It is a heat ray shielding film characterized.
[Chemical formula 1]

The fifth invention is:
The selective wavelength absorbing material is an indole compound represented by [Chemical Formula 1], and R in the formula is a methyl group.
[Chemical formula 1]

The sixth invention is:
The heat ray shielding film further comprises an ultraviolet absorber, and is a heat ray shielding film.
The seventh invention
In the heat ray shielding film, the ultraviolet absorber is at least one selected from a benzotriazole compound and a benzophenone compound.
The eighth invention
The heat ray shielding film is characterized in that the content of the ultraviolet absorber in the heat ray shielding film is 0.5% by mass or more and 10.0% by mass or less.
The ninth invention
When the selective wavelength absorbing material has a light transmittance of 90% or more at a wavelength of 550 nm and a light transmittance of 90% or more at a wavelength of 460 nm, the light transmittance at a wavelength of 420 nm is 15% or less. It is a heat ray shielding film characterized by having a profile.
The tenth invention is
In the heat ray shielding film, the inorganic binder is a silica binder.
The eleventh invention is
The heat ray shielding film further includes an infrared absorbing organic compound.
The twelfth invention
The infrared absorbing organic compound is a phthalocyanine compound, naphthalocyanine compound, imonium compound, diimonium compound, polymethine compound, diphenylmethane compound, triphenylmethane compound, quinone compound, azo compound, pentadiene compound, azomethine compound, squarylium compound, organometallic complex A heat ray shielding film characterized by being at least one selected from cyanine compounds.
The thirteenth invention
The heat ray shielding film, wherein the infrared absorbing organic compound is at least one selected from a phthalocyanine compound and a diimonium compound.
The fourteenth invention is
The heat ray, wherein the weight ratio of the infrared absorbing organic compound and the composite tungsten oxide fine particles is in the range of (composite tungsten oxide fine particles / infrared absorbing organic compound) = 100/5 to 100/100. It is a shielding film.
The fifteenth invention
A heat ray shielding transparent substrate, wherein the heat ray shielding film according to any one of the first to fourteenth inventions is formed on at least one surface of the transparent substrate.
The sixteenth invention is
The transparent base material is a heat ray-shielding transparent base material characterized by being glass.
The seventeenth invention
It is a heat ray shielding transparent base material characterized by yellowness (YI) calculated by JIS K 7373 being -20.0 or more and 10.0 or less.
The eighteenth invention
A heat ray-shielding transparent base material having a yellowness degree (YI) calculated by JIS K 7373 of −20.0 or more and 5.0 or less.
The nineteenth invention
Heat ray shielding transparency characterized by having a visible light transmittance calculated by JIS R 3106 of 70% or more and a solar radiation transmittance of 32.5% or less when the visible light transmittance is 70% or more It is a substrate.
The twentieth invention is
A heat ray shielding transparent base material according to any one of the fifteenth to nineteenth aspects of the present invention is mounted on a window material.
The twenty-first invention
A heat ray shielding transparent base material according to any one of the fifteenth to nineteenth aspects is a building characterized in that it is used as a window material.

  According to the present invention, by using a composite tungsten oxide fine particle and a selective wavelength absorbing material in combination, it is possible to obtain a heat ray shielding film that exhibits excellent optical characteristics and high weather resistance and has a natural color tone. done.

The heat ray shielding film according to the present invention contains composite tungsten oxide fine particles, a dispersant, a selective wavelength absorbing material, an inorganic binder, an ultraviolet absorber if necessary, an infrared absorbing organic compound if desired, and other additives.
Hereinafter, [1] components of the heat ray shielding film, [2] heat ray shielding film, and [3] the transparent substrate on which the heat ray shielding film is formed on the surface will be described in detail.

[1] Constituent component of heat ray shielding film Regarding the heat ray shielding film according to the present invention, first, (1) composite tungsten oxide fine particles, (2) dispersant, (3) selective wavelength absorbing material, (4) ) UV absorber, (5) infrared absorbing organic compound, (6) inorganic binder, and (7) other additives.

(1) Composite tungsten oxide fine particles The composite tungsten oxide fine particles have a general formula MyWOz (where M is Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, Sn, Sb, Al, One or more elements selected from Cu, 0.1 ≦ y ≦ 0.5, 2.2 ≦ z ≦ 3.0), and having a hexagonal crystal structure Is preferred.
In the composite tungsten oxide fine particles, examples of preferable composite tungsten oxide fine particles include Cs _0.33 WO ₃ and Rb _0.33 WO ₃ . However, if the values of y and z are within the above ranges, useful heat ray shielding characteristics can be obtained. The addition amount of the element M is preferably 0.1 or more and 0.5 or less, more preferably around 0.33. This is because the value theoretically calculated from the hexagonal crystal structure is 0.33, and preferable optical characteristics can be obtained with the addition amount before and after this. Moreover, about the range of z, 2.2 <= z <= 3.0 is preferable. This is also in the composite tungsten oxide material expressed by M _y WO _Z, in addition to a mechanism similar tungsten oxide material expressed by the above-mentioned WO _x works, even in z ≦ 3.0, above This is because free electrons are supplied by the addition of the element M. However, from the viewpoint of optical characteristics, 2.45 ≦ z ≦ 3.00 is more preferable.

  The dispersed particle diameter of the composite tungsten oxide fine particles can be appropriately selected depending on the purpose of use of the heat ray shielding film. For example, when the heat ray shielding film is used for applications requiring transparency, the composite tungsten oxide fine particles preferably have a dispersed particle diameter of 40 nm or less. If the composite tungsten oxide fine particles have a dispersed particle size smaller than 40 nm, light is not completely blocked by scattering, and visibility in the visible light region is maintained, and at the same time, transparency is efficiently maintained. Because you can.

  When applying the transparent base material on which the heat ray shielding film or the heat ray shielding dispersion according to the present invention is formed on the surface, for example, in an application in which importance is placed on transparency in the visible light region, such as an automobile windshield, It is preferable to consider scattering reduction by the composite tungsten oxide fine particles. In consideration of the further reduction in scattering, the dispersed particle diameter of the composite tungsten oxide fine particles is 30 nm or less, preferably 25 nm or less.

  The reason why the composite tungsten oxide fine particles have a dispersed particle diameter of 30 nm or less, preferably 25 nm or less is that the composite tungsten oxide fine particles have a wavelength of 400 nm to 780 nm due to geometric scattering or Mie scattering if the dispersed particle diameter of the composite tungsten oxide fine particles is small. This is because light scattering in the visible light region is reduced. By reducing the scattering of the light having the wavelength, it is possible to avoid a situation in which the heat ray shielding film has an appearance like a frosted glass when strong light is irradiated and the clear transparency is lost.

  The above-described situation where the clear transparency is lost can be avoided when the dispersed particle diameter of the composite tungsten oxide fine particles is 40 nm or less, the geometric scattering or Mie scattering described above is reduced, and the Rayleigh scattering region is obtained. Because of that. In the Rayleigh scattering region, the scattered light is reduced in inverse proportion to the sixth power of the particle diameter, so that the scattering is reduced and the transparency is improved as the dispersed particle diameter is reduced. Furthermore, it is preferable that the dispersed tungsten oxide fine particles have a dispersed particle diameter of 25 nm or less because the scattered light is extremely reduced.

As described above, from the viewpoint of avoiding light scattering, it is preferable that the dispersed tungsten oxide fine particles have a small dispersed particle diameter. On the other hand, if the dispersed particle diameter of the composite tungsten oxide fine particles is 1 nm or more, industrial production is possible.
The amount of the composite tungsten oxide fine particles contained in the heat-ray shielding film, per unit area 0.2g ^{/ m 2} ~2.5g ^/ m 2 is desirable.

(2) Dispersant The dispersant used for the production of the composite tungsten oxide fine particle dispersion can be selected according to the application, but it has an amine-containing group, a hydroxyl group, a carboxyl group, or an epoxy group as a functional group. Is preferred. These functional groups are adsorbed on the surface of the composite tungsten oxide fine particles, prevent aggregation of the composite tungsten oxide fine particles, and have an effect of uniformly dispersing the fine particles even in the heat ray shielding film.

Dispersants that can be suitably used in the present invention include phosphate ester compounds, polymer dispersants, silane coupling agents, titanate coupling agents, aluminum coupling agents, and the like. It is not limited. Examples of the polymer dispersant include an acrylic polymer dispersant, a urethane polymer dispersant, an acrylic block copolymer polymer dispersant, a polyether dispersant, and a polyester polymer dispersant.
The amount of the dispersant added is desirably in the range of 10 to 1000 parts by weight, and more preferably in the range of 20 to 200 parts by weight with respect to 100 parts by weight of the composite tungsten oxide fine particles. If the added amount of the dispersant is within this range, the composite tungsten oxide fine particles will not aggregate in the liquid, and dispersion stability is maintained.

(3) Selected Wavelength Absorbing Material The selected wavelength absorbing material according to the present invention is a material that selectively and strongly absorbs light in a certain wavelength region.
As described above, the present inventors have considered the wavelength distribution of the weight coefficient used in the visible light transmittance calculation described in JIS R 3106, and further described in JIS Z 8701 and JIS K 7373. The YI calculation method for plastics was examined. As a result of the study, the composite tungsten oxide fine particles described above absorb light in the vicinity of a wavelength of 420 nm that cannot be sufficiently shielded, and absorb in the vicinity of a wavelength of 550 nm, which is a wavelength region that greatly contributes to the calculation of the visible light transmittance. And a selective wavelength absorbing material that does not absorb light in the vicinity of a wavelength of 460 nm, which has a great influence on YI, has been conceived to be used in combination with the composite tungsten oxide fine particles. That is, the inventors have come up with a configuration in which a material that absorbs light in the vicinity of the wavelength of 420 nm strongly and has no absorption in the vicinity of the wavelength of 460 nm and near the wavelength of 550 nm is used in combination with the composite tungsten oxide fine particles as the selective wavelength absorbing material. By using this configuration, it was possible to obtain a lower solar transmittance without increasing the YI of the heat ray-shielding transparent base material as compared with the case of using the composite tungsten oxide fine particles alone.

Also, for example, when a transparent substrate with a heat ray shielding dispersion formed on the surface is used as a member that requires high visibility, such as an automobile windshield, strong light from direct sunlight, headlamps, etc. When the transparent substrate formed on the surface is irradiated with the heat ray shielding dispersion, fine particles such as composite tungsten oxide fine particles are strongly scattered in the short wavelength region of visible light, and the heat ray shielding dispersion is In some cases, the transparent base material formed in the above becomes a problem of becoming pale and cloudy.
Here, the inventors of the present invention can generate the above-described cloudiness by absorbing the scattered light in the short-wavelength region of visible light generated by the above-described selective wavelength absorption material being scattered by fine particles such as composite tungsten oxide fine particles. It was found that the heat ray shielding film and the heat ray shielding dispersion according to the present invention can also exhibit the effect of enhancing the transparency of the transparent substrate formed on the surface.

As the optical characteristics of the selective wavelength absorbing material according to the present invention, the selective wavelength absorbing material itself excluding the absorption of the medium and the substrate has a light transmittance of 90% or more and a light transmittance of 460 nm. When it is 90% or more, the transmittance of light having a wavelength of 420 nm is preferably 40% or less. Further, when the transmittance of light having a wavelength of 550 nm is 90% or more and the transmittance of light having a wavelength of 460 nm is 90% or more, the transmittance of light having a wavelength of 420 nm is more preferably 15% or less.
This is because when the selected wavelength absorbing material itself has a light transmittance of 90% or more at a wavelength of 550 nm and a light transmittance of 90% or more at a wavelength of 460 nm, the light transmittance at a wavelength of 420 nm is 40% or less. If it has a profile, when the selected wavelength absorbing material and the composite tungsten oxide fine particles are used in combination, the visible light transmittance does not decrease, the YI of the substrate does not significantly increase, and the wavelength This is because sufficient absorption of light near 420 nm can be obtained. As a result, by using the selected wavelength absorbing material and the composite tungsten oxide fine particles in combination, there is no significant change in color tone and the solar radiation transmittance is lower than when the composite tungsten oxide fine particles are used alone. This is because the heat shielding characteristics are improved.

  Specific examples of the selective wavelength absorbing material according to the present invention include benzotriazole compounds, benzophenone compounds, triazine compounds, indole compounds, azomethine compounds, benzotriazolyl compounds, benzoyl compounds, and the like. Among them, it is preferable to use an indole compound or an azomethine compound that has a high absorption coefficient for light having a wavelength of 420 nm and can obtain sufficient absorption at a concentration that does not affect the strength of the inorganic binder. In particular, the effect of the indole compound is clear even when added in a small amount.

The indole compound as the selective wavelength absorbing material according to the present invention will be further described.
When an indole compound is used as the selective wavelength absorbing material according to the present invention, it is preferable to use a compound represented by [Chemical Formula 1]. Here, R in the formula is an alkyl group having 1 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a butyl group, and 2-ethylhexyl group. Examples of the aralkyl group having 7 to 10 carbon atoms include a phenylmethyl group. . Among them, among the indole compounds represented by [Chemical Formula 1], a compound in which R is a methyl group is a selective wavelength absorbing material according to the present invention having a transmittance of 99% for light having a wavelength of 550 nm and a light having a wavelength of 460 nm. The wavelength transmittance at 420 nm when the transmittance is 90% is as low as 0.1% or less and is particularly preferable since it has high weather resistance.
However, even if it is not the indole compound represented by [Chemical Formula 1], the indole compound itself having an indole skeleton excluding the absorption of the medium and the substrate has a transmittance of 90% or more at a wavelength of 550 nm and a wavelength of 460 nm. When the transmittance in light is 90% or more, any indole compound having a transmittance of 40% or less in light with a wavelength of 420 nm can be suitably used as the selective wavelength absorbing material according to the present invention.
[Chemical formula 1]

  The mixing ratio of the composite tungsten oxide fine particles and the selective wavelength absorbing material is preferably such that the value of the weight ratio (composite tungsten oxide fine particles / selective wavelength absorbing material) is in the range of 100/2 to 100/800. More preferably, it is 100 / 5-100 / 800, and it is further more preferable that it is 100 / 10-100 / 400.

  When the mixing ratio of the addition amount of the selective wavelength absorbing material is 100/800 or less, the visible wavelength region is not excessively absorbed by the selective wavelength absorbing material, and the visible light transmittance is maintained. As a result, the solar radiation transmittance is maintained as compared with the case where the composite tungsten oxide fine particles are used alone, and the heat shielding characteristics are maintained. In addition, when the mixing ratio of the addition amount of the selective wavelength absorbing material is 100/800 or less, the absorption in the visible light short wavelength region, which has a great influence on YI, is not excessively strong, and the heat ray shielding is transparent without significantly increasing YI. This is because the color tone of the substrate is maintained.

  On the other hand, if the mixing ratio of the addition amount of the selective wavelength absorbing material is 100/2 or more, only the solar transmittance is reduced while maintaining the color tone of the heat ray-shielding transparent base material and maintaining the visible light transmittance high. I can do it.

  In particular, when an absorption coefficient of light having a wavelength of 420 nm is high as the selective wavelength absorption material, for example, an indole compound or an azomethine compound is used, the mixing ratio of the addition amount of the selective wavelength absorption material is 100 / weight ratio. Even if it is 100 or less and 100/2 or more, compared with the case where the composite tungsten oxide fine particles are used alone, there is no significant change in color tone, and the solar radiation transmittance is lowered, so that the heat shielding characteristics are improved.

(4) Ultraviolet absorber In the heat ray shielding film according to the present invention, when an absorption coefficient of light having a wavelength of 420 nm is high as the selective wavelength absorbing material, for example, an indole compound or an azomethine compound, an ultraviolet absorber is further added. Is also a preferred configuration.
The first reason why it is preferable to further add an ultraviolet absorber to the heat ray-shielding film according to the present invention is that indole compounds and azomethine compounds efficiently absorb short-wavelength visible light, but further add an ultraviolet absorber. This is because effective absorption can be obtained even in the ultraviolet region.
By sufficiently cutting light in the ultraviolet region, a higher temperature rise deterrence effect can be obtained. In addition, it is possible to sufficiently prevent the influence of ultraviolet rays on people and interiors in automobiles and buildings, sunburns, furniture, and deterioration of interiors, on which the heat ray shielding transparent base material according to the present invention is mounted.

The second reason is that by adding an ultraviolet absorber, it is possible to suppress photodegradation of the selective wavelength absorbing material caused by sunlight or the like.
As a result, even if the heat ray shielding transparent substrate according to the present invention is actually used for a long time as a window material for automobiles or buildings, an ultraviolet absorber is further added to the heat ray shielding film according to the present invention. By preserving it, it is possible to suppress light degradation of the selected wavelength absorbing material caused by sunlight or the like.

  Examples of the ultraviolet absorbers described above include organic ultraviolet absorbers such as benzophenone compounds, salicylic acid compounds, HALS compounds, benzotriazole compounds, triazine compounds, benzotriazolyl compounds, and benzoyl compounds, and inorganic materials such as zinc oxide, titanium oxide, and cerium oxide. Examples include ultraviolet absorbers, and among them, benzotriazole compounds and benzophenone compounds are particularly preferable. This is because the benzotriazole compound and the benzophenone compound have very high visible light transmittance and high durability against long-term exposure to strong ultraviolet rays even when a concentration sufficient to absorb ultraviolet rays is added.

  It is preferable that the content rate of the ultraviolet absorber in a heat ray shielding film is 0.5 mass% or more and 10 mass% or less. If the content is 0.5% by mass or more, it is possible to sufficiently absorb ultraviolet light that cannot be absorbed by the selected wavelength absorbing material, and to sufficiently prevent photodegradation of the selected wavelength absorbing material. Because. Further, if the content is 10% by mass or less, the ultraviolet absorber does not precipitate in the heat ray shielding film, and does not significantly affect the strength, adhesive force, and penetration resistance of the film.

  On the other hand, compounds such as benzotriazole compounds, benzophenone compounds, triazine compounds, benzotriazolyl compounds, and benzoyl compounds have light absorption coefficients at a wavelength of 420 nm, although they are lower than indole compounds and azomethine compounds. Therefore, by adding a considerable amount of these compounds to the heat ray shielding film, when the transmittance of light having a wavelength of 550 nm is 90% or more and the transmittance of light having a wavelength of 460 nm is 90% or more, a wavelength of 420 nm The effect that the light transmittance is 40% or less can also be exhibited. According to the said structure, these compounds will serve as the effect of a selective wavelength absorption material and a ultraviolet absorber.

(5) Infrared-absorbing organic compound In the present invention, an infrared-absorbing organic compound having strong absorption in the near-infrared region may be further added to the heat ray shielding film as desired.
Examples of infrared absorbing organic compounds used for this purpose include phthalocyanine compounds, naphthalocyanine compounds, imonium compounds, diimonium compounds, polymethine compounds, diphenylmethane compounds, triphenylmethane compounds, quinone compounds, azo compounds, pentadiene compounds, azomethine compounds, squarylium. Compounds, organometallic complexes, cyanine compounds and the like can be used.
It is preferable to select an infrared absorbing organic compound that dissolves in the inorganic binder constituting the heat ray shielding film described above, since the transparency of the obtained heat ray shielding film is not impaired.

The infrared-absorbing organic compound is more preferably a material that strongly absorbs light in the range from the visible long wavelength region to the near infrared region having a wavelength of 650 nm to 1000 nm. This is because there is a large synergistic effect when the infrared absorbing organic compound having the optical characteristics and the composite tungsten oxide fine particles having strong absorption in the wavelength region of 800 nm or more are used in combination. This is because a higher heat shielding performance can be obtained as compared with the case of using in the above.
From this viewpoint, as the infrared absorbing organic compound used in the present invention, a diimonium compound and a phthalocyanine compound are particularly preferable.
The weight ratio between the infrared absorbing organic compound and the composite tungsten oxide fine particles is preferably in the range of [composite tungsten oxide fine particles / infrared absorbing organic compound] = 100/5 to 100/100.
If the mixing ratio of the addition amount of the infrared absorbing organic compound is more than 100/5 by the above-mentioned weight ratio, the infrared absorbing organic compound strongly increases the light in the visible light long wavelength region from the wavelength range of 650 nm to 1000 nm to the near infrared region. The effect to absorb is acquired and it is preferable. Further, if the mixing ratio of the addition amount of the infrared absorbing organic compound is 100/100 or less in the above-mentioned weight ratio, the wavelength region near 550 nm, which is a wavelength region that greatly contributes to the visible light transmittance calculation by the infrared absorbing organic compound. Therefore, it is possible to avoid a decrease in visible light transmittance. For this reason, even if the visible light transmittance is combined, the heat shielding property is secured, which is preferable.

(6) Inorganic binder The binder according to the present invention includes a compound having a structure in which metal elements or silicon are bonded to each other through oxygen. By adopting a structure in which metal elements or silicon are bonded to each other through oxygen, a heat ray shielding dispersion and a heat ray shielding member having high film strength can be obtained.
Specifically, it includes one or more selected from silane compounds such as alkoxysilane, organosilane, organoalkoxysilane, tetraalkoxysilane, silicate, polyphosphate, silica alumina, titania, cerium oxide, and the like. A binder is mentioned. In addition, it is preferable to contain what is called a silica binder which has a siloxane bond, More preferably, the binder containing organosilane is mentioned. This is because organosilane has a siloxane bond and excellent strength, and also has an organic group such as a methyl group at the terminal group, and therefore has excellent water resistance.

(7) Other additives The heat ray shielding film according to the present invention may further contain general additives as desired. For example, azo dyes, cyanine dyes, quinoline dyes, perylene dyes, carbon black, etc., which are generally used for coloring thermoplastic resins to give an arbitrary color tone as desired. It may be added. Particularly in the present invention, since the light on the short wavelength side of visible light is absorbed, the transmitted light color may be yellowish. Therefore, it is preferable to adjust the color tone of the heat ray shielding film by adding a compound such as a dye or a pigment.
As other additives, a coupling agent, a surfactant, an antistatic agent and the like can be added.

[2] Heat ray shielding film Regarding the heat ray shielding film according to the present invention, (1) a composite tungsten oxide fine particle dispersion, (2) addition of a selective wavelength absorbing material, (3) a coating solution for forming a heat ray shielding dispersion, (4 ) The heat ray shielding film forming method will be described in detail in the order.

(1) Composite tungsten oxide fine particle dispersion The composite tungsten oxide fine particle dispersion according to the present invention is obtained by the following method.
First, composite tungsten oxide fine particles, a solvent, and a dispersing agent are mixed and a dispersion treatment is performed. The dispersion method is not particularly limited as long as a desired dispersed particle size can be obtained. The dispersion treatment is performed until the dispersed particle diameter of the composite tungsten oxide fine particles becomes 200 nm or less. The dispersed particle diameter of the composite tungsten oxide fine particles is preferably 100 nm or less. This is because as the dispersed particle size is smaller, the transparency of the finally obtained heat ray shielding dispersion or heat ray shielding member is improved.
The dispersant is not particularly limited as long as the effect of improving the dispersibility of the composite tungsten oxide fine particles is obtained, and the type of the dispersant is not particularly limited.
The solvent is not particularly limited as long as it does not affect the dispersion of the composite tungsten oxide fine particles. For example, water, alcohols such as ethanol, propanol, butanol, isopropyl alcohol, isobutyl alcohol, diacetone alcohol, ethers such as methyl ether, ethyl ether, propyl ether, esters, acetone, methyl ethyl ketone, diethyl ketone, cyclohexanone, Various organic solvents such as ketones such as methyl isobutyl ketone can be used.
Moreover, you may adjust the pH value of a dispersion liquid by adding an acid and an alkali as needed. Furthermore, in order to further improve the dispersion stability of the fine particles, various surfactants, coupling agents and the like can be added.

(2) Addition of selected wavelength absorbing material The method of adding the selected wavelength absorbing material to the heat ray shielding film is arbitrary, but the selected wavelength absorbing material is required to be uniformly dispersed or dissolved in the binder. The selective wavelength absorbing material according to the present invention is uniformly dispersed or dissolved in the inorganic binder, so that light having a wavelength of 420 nm is sufficiently absorbed, and the selective wavelength absorbing material does not scatter visible light. The transparency of the shielding film is ensured.

There are several methods for bringing the selective wavelength absorbing material into a form in which it is uniformly dispersed or dissolved in the binder. For example, as a solvent for the composite tungsten oxide fine particle dispersion, there is a method in which a solvent capable of dissolving the selective wavelength absorbing material is selected and the selective wavelength absorbing material is dissolved in an appropriate ratio with respect to the composite tungsten oxide fine particle dispersion. . By adopting this method, it is possible to prepare a dispersion containing the composite tungsten oxide fine particles and the selective wavelength absorbing material in an appropriate ratio according to the present invention and dissolving the selective wavelength absorbing material.
Moreover, a liquid thing can be selected as a selective wavelength absorption material, and this can be added to an inorganic binder or a composite tungsten oxide fine particle dispersion.
In addition, a selective wavelength absorbing material having high solubility with respect to the inorganic binder according to the present invention can be selected, and an appropriate amount can be dissolved in advance in the inorganic binder.
Alternatively, the selective wavelength absorbing material can be dissolved in a soluble solvent in advance to obtain a solution, and the solution can be added to the composite tungsten oxide dispersion at an appropriate ratio.
Furthermore, a dispersion of the selective wavelength absorbing material can be prepared in advance, and this can be mixed in an appropriate ratio with respect to the composite tungsten oxide fine particle dispersion. The dispersion of the selective wavelength absorbing material can be easily manufactured by substituting the composite tungsten oxide fine particles with the selective wavelength absorbing material in the above-described method of manufacturing the composite tungsten oxide fine particle dispersion.
Any method can be used as long as the selected wavelength absorbing material can be uniformly dispersed or dissolved in the heat ray shielding film, and can be suitably used as long as the transparency of the obtained heat ray shielding film is ensured. It is done.

The mixing ratio of the composite tungsten oxide fine particles and the selective wavelength absorbing material will be described.
When the weight of the selective wavelength absorbing material is WM, the weight of WM / composite tungsten oxide fine particles is preferably in the range of 1% by mass to 6% by mass with respect to the weight of the composite tungsten oxide fine particles. The weight of tungsten oxide fine particles is more preferably 2% by mass to 6% by mass.
If the addition amount of the selective wavelength absorbing material with respect to the weight (WM) of the composite tungsten oxide fine particles is within the above range, it exhibits higher heat ray shielding characteristics than the case where the composite tungsten oxide fine particles are used alone. This is because there is no adverse effect on the mechanical characteristics and optical characteristics such as film strength in the manufactured heat ray shielding dispersion and heat ray shield.

(3) Coating solution for forming a heat ray shielding dispersion By mixing the composite tungsten oxide fine particle dispersion containing the selective wavelength absorbing material produced by the above-described method and the above-mentioned binder, and diluting with a solvent as necessary. Thus, a coating solution for forming a heat ray shielding dispersion is obtained.
Here, the mixing amount of the binder described above in the coating solution for forming a heat ray shielding dispersion is preferably 5% by mass or more. If the amount of the binder is 5% by mass or more, it is easy to form a heat ray shielding dispersion having a high heat ray shielding effect.

  On the other hand, when the weight ratio of the composite tungsten oxide fine particles to the selective wavelength absorbing material [composite tungsten oxide fine particles / selective wavelength absorbing material] is 100/100 or the weight ratio of the selective wavelength absorbing material is further increased. Increases the proportion of the selective wavelength absorbing material contained in the binder. In this case, avoid the occurrence of so-called bleedout phenomenon in which the stability, hardness, impact resistance and other properties of the binder are reduced, and the selective wavelength absorbing material is precipitated from the binder and impairs transparency and optical properties. Therefore, it is preferable to increase the mixing amount of the binder in the coating solution for forming the heat ray shielding dispersion and to reduce the ratio of the selective wavelength absorbing material in the binder. However, when the mixing amount of the binder in the coating solution for forming the heat ray shielding dispersion is increased, the ratio of the composite tungsten oxide fine particles in the binder also decreases. It is preferable to respond by increasing the thickness of the heat ray shielding film formed when the shielding film is formed.

  Moreover, it is good also as a coating liquid for heat ray shielding dispersion formation by not adding the said binder to composite tungsten oxide fine particle dispersion, but diluting with a solvent suitably. In this case, after forming the heat ray shielding dispersion using the heat ray shielding dispersion forming coating solution, a coating solution containing the binder may be applied, and the heat ray shielding dispersion may be impregnated with the binder.

About the density | concentration of the coating liquid for heat ray shielding dispersion formation, an optimal density | concentration can be suitably selected according to the coating method.
Solvents used for appropriately diluting the coating solution for forming a heat ray shielding dispersion include, for example, alcohols such as ethanol, propanol, butanol, isopropyl alcohol, isobutyl alcohol, diacetone alcohol, methyl ether, ethyl ether, propyl Various organic solvents such as ethers such as ether, esters, acetone, methyl ethyl ketone, diethyl ketone, cyclohexanone, and methyl isobutyl ketone, and water can be used.
When, for example, methyl isobutyl ketone is selected as the dilution solvent, it can be used as a solvent for dissolving the selected wavelength absorbing material described in “(2) Addition of selected wavelength absorbing material”. In this case, it is a preferable configuration because both solvents match.

If necessary, the pH value may be adjusted by adding an acid or alkali to the solvent.
In order to further improve the dispersion stability of the composite tungsten oxide fine particles, various surfactants, coupling agents and the like can be added.
Furthermore, various pigments and dyes may be added to adjust the color tone of the coating solution for forming the heat ray shielding dispersion.

(4) Forming method of heat ray shielding film The heat ray shielding film-forming coating solution produced by the above-described method is applied onto a suitable transparent substrate, the dispersion medium is evaporated, and heat-cured. Thereby, the heat ray shielding film containing the composite tungsten oxide fine particles and the selective wavelength absorbing material is formed on the transparent substrate.
The application method of the coating solution for forming the heat ray shielding dispersion on the transparent substrate surface is not particularly limited as long as it can be uniformly applied. For example, the bar coating method, the gravure coating method, the spray coating method, the dip coating method, the flow coating method. A spin coating method, a roll coating method, a screen printing method, a blade coating method, or the like can be used.
The layer of the heat-ray shielding dispersion containing the composite tungsten oxide fine particles and the selective wavelength absorbing material formed by these coating methods can be formed by sputtering, vapor deposition, ion plating, chemical vapor deposition (CVD), etc. Compared to a layer (film) manufactured by a dry method or a spray method, light in the near-infrared region is efficiently absorbed without using the light interference effect. At the same time, the layer can transmit light in the visible light region.

It is preferable to heat at a temperature of 100 ° C. or higher and lower than 200 ° C. after applying the heat ray shielding film-forming coating solution onto an appropriate transparent substrate surface. By setting the transparent substrate heating temperature to 100 ° C. or higher, the polymerization reaction of the binder according to the present invention contained in the heat ray shielding film can be almost completed. By causing the polymerization reaction to be almost completed, it is possible to avoid the cause of the reduction in visible light transmittance due to the remaining water or organic solvent in the heat ray shielding film. From this viewpoint, the more preferable heating temperature is 150 ° C. or higher.
Moreover, the base-material heating temperature shall be less than 200 degreeC, and the oxidation of composite tungsten oxide microparticles | fine-particles can be avoided and the loss of heat ray shielding ability can be avoided.
The said heat ray shielding film forms a heat ray shielding transparent base material by being formed in at least one surface of a transparent base material. The heat ray shielding film may be formed only on one side of the transparent substrate or on both sides. In particular, when a plastic film or plastic plate having a low hardness is used as the substrate, the heat ray shielding film is preferably formed on both sides. This is because by forming a heat ray shielding film containing an inorganic binder on the surface of a plastic with low scratch resistance and surface hardness, it is possible to impart heat ray shielding characteristics and at the same time impart high scratch resistance and high surface hardness. It is.

The heat ray shielding film produced by the above-described method has high film strength and excellent scratch strength.
Specifically, the surface hardness of the heat ray shielding film according to the present invention was evaluated by 4.4 scratch strength (pencil method) of the JIS K 5600 paint general test method. The surface hardness of the heat ray shielding film was 2H or more, and further 4H or more.

  Further, in the heat ray shielding film according to the present invention obtained by the above method, since the composite tungsten oxide fine particles are conductive materials, when the fine particles are connected to form a continuous film, the mobile phone There is a risk of interference by absorbing and reflecting radio waves. However, when the composite tungsten oxide fine particles are dispersed using, for example, a bead mill and dispersed in the matrix as fine particles, each particle is dispersed in an isolated state, so that radio wave transmission is exhibited. And can be versatile.

As a transparent base material used for a heat ray shield, a film, a resin substrate, a glass substrate, etc. are mentioned, for example. However, when using these materials as a base material, it is calculated | required to have mechanical strength according to each use condition.
In the case of a resin substrate or film, generally, a colorless and transparent resin having transparency and low scattering is suitable, and a resin suitable for the application may be selected. Specifically, polyethylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, polystyrene resin, polypropylene resin, ethylene vinyl acetate copolymer, polyester resin, polyethylene terephthalate (PET) resin, fluorine resin, polycarbonate resin , Acrylic resin, polyvinyl butyral resin, etc., among which polyethylene terephthalate resin is preferred.

  Moreover, when using these resin substrates or films, the surface thereof may be subjected to a surface treatment for the purpose of improving the binding property with an inorganic binder, and a typical treatment method thereof is corona surface treatment, Examples thereof include discharge treatment such as plasma treatment and sputtering treatment, flame treatment, metal sodium treatment, primer layer coating treatment and the like.

When emphasizing the design properties of the resin substrate or film, a pre-colored base material or a shaped base material can be used.
In order to attach the dispersion formed on the resin substrate or the film to a base material such as glass, an adhesive layer and a release film layer may be laminated on the adhesive surface. A film that is easily softened by heat, such as a dryer, may be used so that it can be easily attached to a curved surface like a back window of an automobile.
If a UV absorber is added to the adhesive, UV deterioration of the film or resin can be prevented. Examples of the ultraviolet absorber include benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, CeO ₂ , TiO ₂ , and ZnO.

  In the field where high weather resistance is required, such as when the heat ray shielding transparent substrate according to the present invention is used for mounting on an automobile, it is possible to use glass as the transparent substrate on which the heat ray shielding film is formed on the surface. It is preferable from the viewpoint of cost. In addition to clear glass, any glass can be selected from known glass plates such as gray glass, green glass, UV green glass, and privacy glass.

[3] Transparent base material on which the heat ray shielding film is formed on the surface The transparent base material on which the heat ray shielding film described above is formed has both high visible light transmittance and low solar transmittance, low haze, and natural As a heat ray-shielding transparent substrate having a color tone, it can be used for window materials for automobiles and buildings.

  As an example of the heat shielding characteristics of the heat ray shielding transparent substrate according to the present invention, for example, when the visible light transmittance calculated according to JIS R 3106 is 70% or more, the solar transmittance calculated according to JIS R 3106 is 32. 0.5% or less, preferably 31.5% or less, more preferably 31.0% or less. When the selective wavelength absorbing material according to the present invention is not used in combination, the solar transmittance when the visible light transmittance is 70% or more is considered to be 33% or more, and when the selected wavelength absorbing material according to the present invention is used in combination. The superiority of the present invention that brings about a decrease in solar radiation transmittance, that is, an improvement in heat shielding properties, is apparent.

When the heat ray shielding transparent base material according to the present invention is used as a window material in an automobile or a building, it is preferable to have a natural color tone (transparent or achromatic color). In particular, assuming that the heat ray-shielding transparent base material according to the present invention is used for a front side glass of an automobile, it is preferable that the color of the fluoroscopic image can be normally identified in order to ensure safety during driving.
From this viewpoint, for the heat ray-shielding transparent substrate according to the present invention, for example, in the color discrimination test based on JIS R 3211 and JIS R 3212 that define the performance required for automotive safety glass, the color of the fluoroscopic image is It is preferable that it can be normally identified.
Here, when the YI of the heat ray shielding transparent substrate according to the present invention is -20 or more and 10 or less, the color of the fluoroscopic image can be normally identified. And in the mixing ratio of the composite tungsten oxide microparticles | fine-particles which concern on this invention mentioned above, and the selection wavelength absorption material, by taking the above-mentioned structure, the value of YI of the heat ray shielding transparent base material concerning this invention is -20 or more and 10 It can be as follows. In addition, by setting the YI of the heat ray-shielding transparent base material to -20 or more and 5 or less in the mixing ratio of the composite tungsten oxide fine particles according to the present invention and the selective wavelength absorbing material described above, the color of the fluoroscopic image is further easily identified. It is more preferable because it is possible.

[4] Summary As described above, according to the present invention, the composite tungsten oxide fine particles and the selective wavelength absorbing material are both contained in the binder, thereby maintaining high transmittance in the visible light region and low solar transmittance. It is possible to produce a heat ray shielding film having a natural color tone and a heat ray shielding transparent base material at a low cost.

  Furthermore, since the heat ray shielding transparent base material which concerns on this invention contains an inorganic binder, the effect that it becomes difficult to get a damage | wound can also be given by being formed in the surface of a transparent base material. Also from this viewpoint, the heat ray-shielding transparent base material according to the present invention is a glass embedded in automobiles, front side glass, back side glass and rear glass, door glass and window glass of railway vehicles, indoor door glass, and window glass in buildings such as buildings. It can be suitably used for various purposes such as indoor door glass, indoor display showcases and show windows.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.
Further, the transmittance of light having a wavelength of 420 nm, a wavelength of 460 nm, and a wavelength of 550 nm of the selective wavelength absorbing material in each example is a quartz glass cell having an optical path length of 1 cm obtained by dissolving a liquid in which the selective wavelength absorbing material is dissolved in an organic solvent at an appropriate concentration And measured using a spectrophotometer U-4000 manufactured by Hitachi, Ltd. The baseline was drawn with only the organic solvent used for dissolution in the same cell. As the organic solvent for dissolving the selected wavelength absorbing material in this measurement, one kind arbitrarily selected from toluene, methyl isobutyl ketone and N-methyl-2-pyrrolidinone according to the solvent solubility of the selected wavelength absorbing material is used. It was.
The visible light transmittance and the solar radiation transmittance of the heat ray shielding transparent base material were similarly measured using a spectrophotometer U-4000. In addition, the said solar transmittance is an parameter | index which shows the heat ray shielding performance of a heat ray shielding transparent base material. YI of the heat ray-shielding transparent substrate was calculated based on JIS Z 8701 and JIS K 7373 from the transmittance of light having a wavelength of 380 to 780 nm measured using a spectrophotometer U-4000. The dispersion particle diameter of the composite tungsten oxide fine particles in the dispersion was measured with a microtrack manufactured by Nikkiso Co., Ltd.

Example 1
20% by mass of composite tungsten oxide fine particles Cs _0.33 WO ₃ (hereinafter referred to as fine particles a) and an acrylic dispersant having an amine-containing group as a functional group (amine value 48 mgKOH / g, decomposition temperature 250) C.) 10% by mass of acrylic dispersant (hereinafter referred to as Dispersant a) and 70% by mass of toluene were weighed. These were loaded into a paint shaker containing 0.3 mmφZrO ₂ beads and pulverized and dispersed for 10 hours to obtain a plasticizer dispersion of composite tungsten oxide fine particles (hereinafter referred to as fine particle dispersion A). . The dispersed particle size in the fine particle dispersion A was measured and found to be 31 nm.

  BONSORB UA-3911 (CAS No. 142676-93-5, [Chemical Formula 1], manufactured by Orient Chemical Co., Ltd.), which is an indole compound, is an indole compound as a selective wavelength absorbing material, and an indole compound in which R is a methyl group, transmission of light at a wavelength of 550 nm When the transmittance is 99% and the transmittance of light having a wavelength of 460 nm is 90%, the wavelength transmittance at 420 nm is 0%, hereinafter referred to as indole compound A.) is dissolved in methyl ethyl ketone, and the indole compound A concentration is 2 % Methyl ethyl ketone solution (hereinafter referred to as “solution A”).

  The solution A is added to the fine particle dispersion A so that the weight ratio of the composite tungsten oxide fine particles to the selective wavelength absorbing material [composite tungsten oxide fine particles / selected wavelength absorbing material] is 100/20. Produced. A silica binder having a solid content of 25% containing organosilane is mixed with the mixed solution so that the solid content of the silica binder is 950.0 parts by weight with respect to 100 parts by weight of the composite tungsten oxide fine particles, thereby forming a heat ray shielding dispersion. Coating solution (hereinafter sometimes abbreviated as “coating solution”).

  This coating solution was applied and formed into a film on a transparent substrate (inorganic clear glass) using a bar coater. This film was dried at 180 ° C. for 30 minutes, and the dispersion medium was evaporated and cured to produce a heat ray shielding transparent base material in which a heat ray shielding film was formed on the transparent base material. Table 1 shows the optical characteristics of the manufactured heat ray-shielding transparent substrate.

[Examples 2 to 17]
The type of the selective wavelength absorbing material described in Example 1 and the weight ratio of the composite tungsten oxide fine particles to the selective wavelength absorbing material in the composition for producing a heat ray shielding film [composite tungsten oxide fine particles / selected wavelength. Absorbing material] was changed as shown in Table 1 and the addition method of the selective wavelength absorbing material was changed as described later. A substrate was obtained. And the optical characteristic of the heat ray shielding transparent base material concerning the said Examples 2-17 was measured similarly to Example 1, and the said optical characteristic measurement result was shown in Table 1.

当該アゾメチン化合物Ｂを、Ｎ−メチル−２−ピロリジノンに溶解してアゾメチン化合物Ｂ濃度２％のＮ−メチル−２−ピロリジノン溶液を作製し、これを複合タングステン酸化物微粒子分散液に所定の割合で添加した。
実施例９〜１１においては、選択波長吸収材料としてベンゾトリアゾール化合物であるＢＡＳＦ製ＴＩＮＵＶＩＮ １０９（ＣＡＳ Ｎｏ．８３０４４−８９−７、〔化学式３〕で示され、波長５５０ｎｍの光の透過率を９９％、波長４６０ｎｍの光の透過率を９０％としたときの４２０ｎｍの波長透過率は０％、以下、ベンゾトリアゾール化合物Ｃと記載する。）を用いた。
〔化学式３〕

当該ベンゾトリアゾール化合物Ｃは液状であり、そのまま複合タングステン酸化物微粒子分散液に所定の割合で添加した。
実施例１２〜１４においては、選択波長吸収材料としてトリアジン化合物であるＢＡＳＦ製ＴＩＮＵＶＩＮ ４７９（ＣＡＳ Ｎｏ．２０４８４８−４５−３、〔化学式４〕で示され、波長５５０ｎｍの光の透過率を９９％、波長４６０ｎｍの光の透過率を９０％としたときの４２０ｎｍの波長透過率は１５％、以下、トリアジン化合物Ｄと記載する。）を用いた。
〔化学式４〕

当該トリアジン化合物Ｄを、メチルイソブチルケトンに溶解してトリアジン化合物Ｄ濃度１０％のメチルイソブチルケトン溶液を作製し、これを複合タングステン酸化物微粒子分散液に適切な割合で添加した。
実施例１５〜１７においては、選択波長吸収材料としてベンゾフェノン化合物である大和化成製ＤＡＩＮＳＯＲＢ Ｐ−６（ＣＡＳ Ｎｏ．１３１−５５−４、〔化学式５〕で示され、波長５５０ｎｍの光の透過率を９７％、波長４６０ｎｍの光の透過率を９２％としたときの４２０ｎｍの波長透過率は２５％、以下、ベンゾフェノン化合物Ｅと記載する。）を用いた。
〔化学式５〕

当該ベンゾフェノン化合物Ｅを、メチルイソブチルケトンに溶解してベンゾフェノン化合物Ｅ濃度５％のメチルイソブチルケトン溶液を作製し、これを複合タングステン酸化物微粒子分散液に適切な割合で添加した。 In Examples 2 to 5, the indole compound A described above was used as the selective wavelength absorbing material. As in Example 1, indole compound A was dissolved in methyl ethyl ketone to prepare a methyl ethyl ketone solution having an indole compound A concentration of 2%, and this was added to the composite tungsten oxide fine particle dispersion at a predetermined ratio.
In Examples 6 to 8, it is shown by BONASORB UA-3701 (CAS No. 55567-59-4, [Chemical Formula 2], manufactured by Orient Chemical Co., Ltd.), which is an azomethine compound as a selective wavelength absorbing material, and has a light transmittance of 550 nm. Was 98% and the transmittance of light at a wavelength of 460 nm was 90%, the wavelength transmittance at 420 nm was 0%, hereinafter referred to as azomethine compound B).
[Chemical formula 2]

The azomethine compound B is dissolved in N-methyl-2-pyrrolidinone to prepare an N-methyl-2-pyrrolidinone solution having a concentration of 2% azomethine compound B, which is added to the composite tungsten oxide fine particle dispersion at a predetermined ratio. Added.
In Examples 9 to 11, a benzotriazole compound TINUVIN 109 (CAS No. 83044-89-7, [Chemical Formula 3]), which is a benzotriazole compound as a selective wavelength absorbing material, has a transmittance of 99% for light having a wavelength of 550 nm. The wavelength transmittance at 420 nm when the transmittance of light having a wavelength of 460 nm was 90% was 0%, and hereinafter referred to as benzotriazole compound C).
[Chemical formula 3]

The benzotriazole compound C is in a liquid state and added as it is to the composite tungsten oxide fine particle dispersion at a predetermined ratio.
In Examples 12 to 14, TINUVIN 479 (CAS No. 204848-45-3, [Chemical Formula 4], manufactured by BASF, which is a triazine compound as a selective wavelength absorbing material, 99% transmittance of light having a wavelength of 550 nm, When the transmittance of light having a wavelength of 460 nm is 90%, the wavelength transmittance of 420 nm is 15%, which is hereinafter referred to as triazine compound D).
[Chemical formula 4]

The triazine compound D was dissolved in methyl isobutyl ketone to prepare a methyl isobutyl ketone solution having a triazine compound D concentration of 10%, and this was added to the composite tungsten oxide fine particle dispersion at an appropriate ratio.
In Examples 15 to 17, DAINSORB P-6 (CAS No. 131-55-4, [Chemical Formula 5], manufactured by Daiwa Kasei Co., Ltd.), which is a benzophenone compound as a selective wavelength absorbing material, has a light transmittance of 550 nm. The wavelength transmittance of 420 nm when the transmittance of light having a wavelength of 97% and a wavelength of 460 nm was 92% was 25%, and hereinafter referred to as benzophenone compound E).
[Chemical formula 5]

The benzophenone compound E was dissolved in methyl isobutyl ketone to prepare a methyl isobutyl ketone solution having a benzophenone compound E concentration of 5%, and this was added to the composite tungsten oxide fine particle dispersion at an appropriate ratio.

[Comparative Example 1]
A heat ray shielding transparent base material according to Comparative Example 1 was obtained in the same manner as Example 1 except that the selective wavelength absorbing material was not added. And the optical characteristic of the heat ray shielding transparent base material concerning the said comparative example 1 was measured similarly to Example 1. FIG. Table 1 shows the measurement results of the optical characteristics of the heat ray-shielding transparent substrate according to Comparative Example 1.

[Comparative Examples 2 to 4]
The kind of the selective wavelength absorbing material described in Example 1 and the weight ratio of the composite tungsten oxide fine particles to the selective wavelength absorbing material in the composition for producing a heat ray-shielding transparent substrate [composite tungsten oxide fine particles / selected wavelength Absorbing material] was changed as shown in Table 1, and the addition method of the selective wavelength absorbing material was changed as described later, respectively, and heat ray shielding according to Comparative Examples 2 to 4 was performed in the same manner as in Example 1. A membrane was obtained. And the optical characteristic of the heat ray shielding film which concerns on the said Comparative Examples 2-4 was measured similarly to Example 1. FIG. The results are shown in Table 1.

  In addition, in the comparative examples 2-3, the indole compound A mentioned above was used as a selective wavelength absorption material. Specifically, in the same manner as in Example 1, indole compound A was dissolved in methyl ethyl ketone to prepare a methyl ethyl ketone solution having an indole compound A concentration of 2%, and this was added to the composite tungsten oxide fine particle dispersion at a predetermined ratio. did.

In Comparative Example 4, C.I. which is a quinophthalone compound. I. Solvent Yellow 33 (CAS No. 8003-22-3, represented by [Chemical Formula 6]), wavelength transmittance of 420 nm when the transmittance of light having a wavelength of 550 nm is 99% and the transmittance of light having a wavelength of 460 nm is 90% The rate was 55%, hereinafter referred to as quinophthalone compound F). The quinophthalone compound F is dissolved in N-methyl-2-pyrrolidinone to prepare an N-methyl-2-pyrrolidinone solution having a quinophthalone compound F concentration of 2%, and this is added to the composite tungsten oxide fine particle dispersion at a predetermined ratio. did.
[Chemical formula 6]

[Example 18]
To the fine particle dispersion A described in Example 1, a methyl ethyl ketone solution of indole compound A is added as a selective wavelength absorbing material, and diimonium compound CIR-RL (hereinafter referred to as diimonium compound G) manufactured by Nippon Carlit is absorbed in infrared. Added as an organic compound. The weight ratio of the composite tungsten oxide fine particles to the selected wavelength absorbing material [composite tungsten oxide fine particles / selected wavelength absorbing material] is 100/20, and the weight ratio of the composite tungsten oxide fine particles to the infrared absorbing organic compound [ Mixed tungsten oxide fine particles / infrared absorbing organic compound] was mixed so as to be 100/5 to prepare a mixed solution.
A silica binder containing 25% solids containing organosilane was mixed with the mixed solution so that the solid content of the silica binder was 780.0 parts by weight with respect to 100 parts by weight of the composite tungsten oxide fine particles.

  This coating solution was applied and formed on a substrate (inorganic glass) using a bar coater to obtain a heat ray shielding film according to Example 11. Then, the optical characteristics of the heat ray shielding film according to Example 11 were measured in the same manner as in Example 1.

  The type of composite tungsten oxide fine particles in Example 11, the type of selective wavelength absorbing material, and the weight ratio of the composite tungsten oxide fine particles to the selective wavelength absorbing material in the composition for producing a heat ray shielding film [composite tungsten oxide fine particles / Selective wavelength absorbing material], type of infrared absorbing organic compound, and weight ratio of the composite tungsten oxide fine particles to the infrared absorbing organic compound in the composition for producing a heat ray shielding film [composite tungsten oxide fine particles / infrared absorption] The organic compound] is shown in Table 1. Furthermore, Table 1 shows the measurement results of optical characteristics of the heat ray shielding film according to Example 18.

[Example 19]
The indole compound A and the benzotriazole compound C as an ultraviolet absorber are added to the fine particle dispersion A described in Example 1, and the weight ratio of the composite tungsten oxide fine particles to the selective wavelength absorbing material [composite tungsten oxide fine particles / Selected wavelength absorbing material] was 100/20, and a mixed solution in which the content of the ultraviolet absorber in the heat ray shielding film was 0.5% by mass was produced. A silica binder containing 25% solids containing organosilane was mixed with this mixed solution so that the solid content of the silica binder was 350.0 parts by weight with respect to 100 parts by weight of the composite tungsten oxide fine particles.
This coating solution was applied and formed on a substrate (inorganic glass) using a bar coater to obtain a heat ray shielding film according to Example 19.

  The optical characteristics of the heat ray shielding film according to Example 19 were measured in the same manner as in Example 1. The type of composite tungsten oxide fine particles in Example 19, the type of selective wavelength absorbing material, and the weight ratio of the composite tungsten oxide fine particles to the selective wavelength absorbing material in the composition for producing a heat ray shielding film [composite tungsten oxide Fine particle / selective wavelength absorbing material], type of infrared absorbing organic compound, and weight ratio of the composite tungsten oxide fine particle to the infrared absorbing organic compound in the composition for producing a heat ray shielding film [composite tungsten oxide fine particle / infrared ray Absorbable organic compounds] are shown in Table 1. Further, Table 1 shows the measurement results of optical characteristics of the heat ray shielding film in Example 19.

[Examples 20 to 22]
Except having changed the kind of ultraviolet absorber which was demonstrated in Example 19, and the content rate of the ultraviolet absorber in a heat ray shielding film as Table 1, it carried out similarly to Example 19, and changed to Examples 20-22 The heat ray shielding transparent base material which concerns was obtained.
And the optical characteristic of the heat ray shielding transparent base material which concerns on the said Examples 20-22 was measured similarly to Example 1. FIG. The results are shown in Table 1.
As the ultraviolet absorber, benzotriazole compound C was used in Example 20, and benzophenone compound E was used in Examples 21-22.
[Example 23]
A heat ray shielding transparent substrate according to Example 23 was produced in the same manner as in Example 1 except that Rb _0.33 WO ₃ fine particles were used as the composite tungsten oxide fine particles instead of Cs _0.33 WO ₃ fine particles. . And the optical characteristic of the heat ray shielding transparent base material concerning the said Example 23 was measured similarly to Example 1. FIG. The optical characteristic measurement results are shown in Table 1. Incidentally, a 27nm was measured dispersed particle size of the _{Rb 0.33} WO ₃ fine particle dispersion produced in Example 23.

  For comparison, the wavelength transmittance at 420 nm was measured when the light transmittance at a wavelength of 550 nm and a wavelength of 460 nm in the selected wavelength absorbing material itself excluding the absorption of the medium and the substrate was 90% or more. As a result, indole compound A, azomethine compound B, benzotriazole compound C, triazine compound D and benzophenone compound E were 40% or less, while quinophthalone compound F was 40% or more. The results are shown in Table 2.

[Evaluation of Examples 1 to 17, Examples 19 to 23, and Comparative Examples 1 to 4]
In Examples 1 to 17 and Examples 19 to 23, the selected wavelength absorbing material was used in combination with the composite tungsten oxide fine particles at a predetermined ratio, so that the solar radiation lower than that of Comparative Example 1 in which the selected wavelength absorbing material was not used together. Transmittance was obtained. Further, the yellowness value YI of the heat ray-shielding transparent base material did not exceed 10, and there was little change in the color tone due to the combined use of the selective wavelength absorbing material.
In addition, in Examples 19 to 22, by using an ultraviolet absorber in combination, a lower solar transmittance was obtained than when only the selective wavelength absorbing material and the composite tungsten oxide fine particles were used in combination.
On the other hand, in Comparative Example 2, since the addition amount of the selective wavelength absorbing material was small, sufficient light absorption could not be obtained, and only the same solar radiation transmittance as Comparative Example 1 in which the selective wavelength absorbing material was not used together was obtained. There wasn't. In Comparative Example 3, since the addition amount of the selective wavelength absorbing material was too large, the yellowness value YI increased to 10 or more, and the color tone of the heat ray-shielding transparent base material changed greatly. In Comparative Example 4, since the quinophthalone compound F having a weak absorption of 420 nm with respect to the transmittance of light having a wavelength of 550 nm and a wavelength of 460 nm was used as the selective wavelength absorbing material, the yellowness value YI rose to 10 or more, and the heat ray The color tone of the transparent shielding substrate has changed greatly.

[Evaluation of Example 18]
In Example 18, in addition to the use of the selective wavelength absorbing material in combination with the composite tungsten oxide fine particles, the absorption by the composite tungsten oxide fine particles and the selective wavelength absorbing material is slightly low, and light having a wavelength of about 800 to 1100 nm is absorbed. By using the infrared absorbing organic compound in combination, a very low solar transmittance was obtained.

Claims (21)

Formula _M y WO _Z (where, M is, Cs, Rb, K, Tl , In, Ba, Li, Ca, Sr, Fe, 1 or more elements selected Sn, Sb, Al, from Cu, 0 0.1 ≦ y ≦ 0.5, 2.2 ≦ z ≦ 3.0), and a composite tungsten oxide fine particle having a hexagonal crystal structure, a selective wavelength absorbing material, and an inorganic binder A heat shielding film,
The selective wavelength absorbing material is an indole compound;
The weight ratio of the composite tungsten oxide fine particles to the selective wavelength absorbing material is in the range of (composite tungsten oxide fine particles / selective wavelength absorbing material) = 100/2 to 100/800,
The selective wavelength absorbing material has a transmittance of light having a wavelength of 550 nm of 90% or more and a transmittance of light having a wavelength of 420 nm when the transmittance of light having a wavelength of 460 nm is 90% or more. A heat ray shielding film having a profile. 2. The heat ray shielding film according to claim 1, wherein the composite tungsten oxide fine particles are at least one selected from Cs _0.33 WO ₃ and Rb _0.33 WO ₃ .   The heat ray shielding film according to claim 1 or 2, wherein the composite tungsten oxide fine particles are fine particles having a dispersed particle diameter of 40 nm or less. The selective wavelength absorbing material is an indole compound represented by [Chemical Formula 1], and R in the formula is an alkyl group having 1 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms. The heat ray shielding film according to any one of claims 1 to 3, wherein
[Chemical formula 1]

The heat ray shielding film according to claim 4, wherein the selective wavelength absorbing material is an indole compound represented by [Chemical Formula 1], and R in the formula is a methyl group.
[Chemical formula 1]

The said heat ray shielding film contains a ultraviolet absorber further, The heat ray shielding film in any one of Claim 1 to 5 characterized by the above-mentioned . The heat ray shielding film according to claim 6, wherein the ultraviolet absorber is at least one selected from a benzotriazole compound and a benzophenone compound. The heat ray shielding film according to claim 6 or 7, wherein a content of the ultraviolet absorber in the heat ray shielding film is 0.5 mass% or more and 10.0 mass% or less. When the selective wavelength absorbing material has a light transmittance of 90% or more at a wavelength of 550 nm and a light transmittance of 90% or more at a wavelength of 460 nm, the light transmittance at a wavelength of 420 nm is 15% or less. It has a profile, The heat ray shielding film in any one of Claim 1 to 8 characterized by the above-mentioned . The heat ray shielding film according to claim 1 , wherein the inorganic binder is a silica binder. The heat ray shielding film according to any one of claims 1 to 10, wherein the heat ray shielding film further contains an infrared absorbing organic compound. The infrared absorbing organic compound is a phthalocyanine compound, naphthalocyanine compound, imonium compound, diimonium compound, polymethine compound, diphenylmethane compound, triphenylmethane compound, quinone compound, azo compound, pentadiene compound, azomethine compound, squarylium compound, organometallic complex The heat ray shielding film according to claim 11, wherein the heat ray shielding film is at least one selected from cyanine compounds. The heat ray shielding film according to claim 11, wherein the infrared absorbing organic compound is at least one selected from a phthalocyanine compound and a diimonium compound. Claims wherein the weight ratio of the infrared absorbing organic compound and the composite tungsten oxide fine particles, characterized in that it is in the range of (composite tungsten oxide microparticles / infrared absorbing organic compound) = 100 / 5-100 / 100 Item 14. The heat ray shielding film according to any one of Items 11 to 13 . The heat ray shielding transparent base material in which the heat ray shielding film in any one of Claim 1 to 14 is formed on the at least single side | surface of a transparent base material. The heat ray shielding transparent base material according to claim 15, wherein the transparent base material is glass. The heat ray shielding transparent base material according to claim 15 or 16 , wherein yellowness (YI) calculated by JIS K 7373 is -20.0 or more and 10.0 or less. The heat ray-shielding transparent substrate according to claim 15 or 16, wherein a yellowness degree (YI) calculated by JIS K 7373 is -20.0 or more and 5.0 or less. JIS and the visible light transmittance which is calculated by R 3106 is 70% or more, and claims 15 to solar radiation transmittance when the visible light transmittance of 70% or more is equal to or less than 32.5% The heat ray shielding transparent base material according to any one of 18 . An automobile, wherein the heat ray shielding transparent base material according to any one of claims 15 to 19 is mounted as a window material. A building, wherein the heat ray shielding transparent base material according to any one of claims 15 to 19 is used as a window material.